The relationship between header type and head acceleration during heading in male youth football players.

OBJECTIVE: To explore head impact magnitude (linear head acceleration and rotational velocity) during heading for four different header types in youth male footballers. A secondary objective was to explore whether head impact magnitude was influenced by player-related factors (i.e. age, neck strength). DESIGN: An observational field-based research design was utilised for this research. PARTICIPANTS: 27 youth male footballers (mean age14.81, SD1.88) from one football club. MAIN OUTCOME MEASURES: Peak linear acceleration and peak angular velocity were measured during four different header types (two from 15-m and two from 5-m). Maximal isometric neck strength of each player was also assessed (flexors, extensors, left and right-side flexors). RESULTS: Statistically significant differences were observed between header type and both peak linear acceleration (F(3,78) = 60.90, R2 = 0.76, p=<0.001) and peak angular velocity (F(3,78) = 43.63, R2 = 0.75, p=<0.001). In terms of players related factors, for linear acceleration, 6% (P = 0.008) of the variance was predicted by age, and for angular velocity, 12% (P = 0.003) was predicted by age, with neck strength accounting for <9% of the variance. CONCLUSIONS: In this youth cohort, head impact magnitude during heading is influenced by the type of header being performed.

Where are We Headed? Evidence to Inform Future Football Heading Guidelines.

Given the scientific and public concern regarding the short-, medium- and long-term consequences of heading on brain health, being proactive about developing and implementing guidelines that help reduce the burden (volume, impact magnitude and injury risk) of heading in young and beginner players appears justified. This narrative review explores the evidence underpinning strategies that could be incorporated into future heading guidelines to reduce heading burden in players across all levels of football. A four-step search strategy was utilised to identify all data-based papers related to heading in football. Eligibility criteria for inclusion were: (1) original data, (2) study population included football players, (3) outcome measures included one or more of the following: number of headers, measurement of head acceleration during heading, or head/brain injury incidence, and (4) published in English or English translation available. In total, 58 papers were included that outlined strategies based on (1) game or team development, (2) player skill development and (3) equipment. In particular, greater emphasis existed for small-sided games (particularly in young players) where fewer headers are observed when compared with the conventional 11 versus 11 game, as well as reducing headers from goal kicks and corners. Evidence also existed for developing a heading coaching framework that focusses on technical proficiency as well as neuromuscular neck exercises integrated into general injury reduction exercise programs, enforcement of rules related to deliberate head contact and using lower-pressure match and training balls. To mitigate potential risks of heading on brain health, a number of pragmatic strategies have been examined in scientific studies and may be considered as part of future heading guidelines.

Intestinal fatty acid binding protein (I-FABP) and CXC3L1 evaluation as biomarkers for patients at high-risk for coeliac disease in Johannesburg, South Africa.

Coeliac disease (CD) is an autoimmune disorder and one of the few gastroenteropathies with accurate serological testing. CD serology has decreased accuracy for patients on a gluten-free diet and for monitoring mucosal healing. New ancillary tests would, therefore, be useful. Intestinal Fatty Acid Binding Protein (I-FABP) and CX3CL1 (Fractalkine) are two promising biomarkers for CD but haven't been examined in patients who are at a high-risk for CD such as patients with type one diabetes (TID). This study, therefore, aimed to investigate serum levels of I-FABP and CX3CL1 in a cohort of South African patients with TID at a high-risk of developing CD. The serum I-FABP levels were significantly higher in CD-positive patients compared to CD-negative individuals (p = 0.03). No significant differences in the serum CX3CL1 levels were detected although this may reflect the impact of the comorbid autoimmune diseases had on the serum CX3CL1 levels. In conclusion, this study is the first to assess the levels of these biomarkers in a multiethnic population with comorbid autoimmune disease and determined I-FABP to be the more promising biomarker in such clinical contexts. Future research should focus on a diverse biomarker panel and longitudinal follow-up of patients at a high-risk for CD.

Proof of concept: hypovolemic hyponatremia may precede and augment creatine kinase elevations during an ultramarathon.

PURPOSE: It is not known if exercise-associated hyponatremia (EAH) is a cause or consequence of exertional rhabdomyolysis (ER).We hypothesized that osmotic stress (EAH) coupled with mechanical stress (running) potentiated muscle cell breakdown (ER). This concept would be supported if a nadir in serum sodium concentration ([Na(+)]) temporally preceded peak creatine kinase levels (CK) during an ultramarathon run. METHODS: Fifteen participants ran ≥104 km and had blood drawn: prior to start; 53; 104 km; and 24-h post run. Serum [Na(+)], CK, urea, creatinine and estimated glomerular filtration rate (eGFR) were measured from serial blood samples. Two-way repeated-measures ANOVA was used to examine differences regarding both race distance and natremia status. RESULTS: Ten of 15 participants demonstrated EAH (serum [Na(+)] <135 mmol/L) at least once during serial testing. Participants were categorized post hoc into one of three natremia groups based on lowest recorded [Na(+)]: (1) <129 mmol/L (n = 3; moderate EAH); (2) between 129 and 134 mmol/L (n = 7; mild EAH); and (3) >134 mmol/L (n = 5; normonatremia). Participants with lowest [Na(+)] demonstrated highest CK values at subsequent checkpoints. Significant natremia group differences noted at the 53 km point (p = 0.0002) for [Na(+)] while significant natremia group effect noted for CK seen at the 24-h post-finish testing point (p = 0.02). Significant natremia group effects noted for renal biomarkers, with the moderate EAH group documenting the lowest eGFR (p = 0.005), and highest serum urea (p = 0.0006) and creatinine (p < 0.0001) levels. Hyponatremic runners had lower post-race urine [Na(+)] than normonatremic runners (26 ± 15 vs. 89 ± 79 mmol/L; p = 0.03). CONCLUSIONS: Preliminary data support the possibility that transient hypovolemic EAH may precede and augment CK during an ultramarathon.

Incidence of Exercise-Associated Hyponatremia and Its Association With Nonosmotic Stimuli of Arginine Vasopressin in the GNW100s Ultra-endurance Marathon.

OBJECTIVES: (1) To examine the incidence of exercise-associated hyponatremia (EAH) during and after an ultramarathon and (2) to evaluate hypothesized nonosmotic stimuli [interleukin-6 (IL-6), hypoglycemia, ambient temperature] with arginine vasopressin (AVP) concentrations in hyponatremic versus normonatremic runners. DESIGN: Prospective cohort study. SETTING: The Great North Walk 100s ultramarathons. PARTICIPANTS: Fifteen runners participated in either 103.7- or 173.7-km ultramarathons. MAIN OUTCOME MEASURES: Serum sodium concentration ([Na]) and AVP concentration. Secondary outcome measures included IL-6, blood glucose, ambient temperature, weight change, fluid consumption, and use of nonsteroidal anti-inflammatory drugs (NSAIDs). RESULTS: Postrace EAH incidence was 4 of 15 runners, whereas EAH incidence at any point during the race was in 10 of 15 runners. A significant positive correlation was noted between AVP and IL-6 (r = 0.31, P < 0.05) but not between AVP and blood glucose (r = 0.09, nonsignificant) or ambient temperature (r = -0.12, NS). Subgroup analysis revealed that the correlation between AVP and IL-6 was significant in hyponatremic (r = 0.37, P < 0.05) but not normonatremic runners (r = 0.31, NS). Hyponatremic runners lost less weight than normonatremic runners (2.5 vs. 3.7 kg, P < 0.05, respectively) despite similar fluid consumption. Seven of 10 hyponatremic runners consumed NSAIDs versus 0 of 5 normonatremic runners. CONCLUSIONS: Exercise-associated hyponatremia incidence mid-race is higher than postrace, suggesting that 40% of runners are able to self-correct low serum [Na] status during an ultramarathon. Interleukin-6 seems to be the main nonosmotic stimulus associated with AVP in hyponatremic runners. Nonsteroidal anti-inflammatory ingestion is more common in hyponatremic versus normonatremic runners. CLINICAL RELEVANCE: Exercise-associated hyponatremia associated with nonosmotic AVP secretion may be more common during ultramarathon races without discriminatory clinical symptomatology.